JP2006182404A - Method for manufacturing cylindrical opening for synthetic resin bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a cylindrical opening for a synthetic resin bag improving manufacturing efficiency by reducing the number of processes and decreasing a manufacturing cost by simultaneously heat-welding a lower part opening cylinder and an upper part opening cylinder to a cylindrical opening main body in manufacturing the cylindrical opening fitted to a top board of the synthetic resin bag. <P>SOLUTION: In the cylindrical opening main body 12 which is formed of a thermoplastic synthetic resin into a cylindrical shape with a specified length and whose inside layer is heat-welded with the same material and whose outside layer is be heat-welded between the same material and the other material, the lower half from a just middle position in the longitudinal direction is folded back outside to form a double cylindrical condition. The upper part opening cylinder 14 is fitted to the inside of the end part on the freely separated side of this cylindrical opening main body 12, and the lower part opening cylinder 13 is fitted to its outside. Under this condition, the fitted parts of the cylindrical opening main body 12 and the upper part opening cylinder 14 and the lower part opening cylinder 13 are simultaneously heat-welded. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a cylindrical opening for a synthetic resin bag, which is attached to a top plate of a synthetic resin bag used as an interior container for a shape retaining member and fills a synthetic bag with a stored bag.

  For storage and transportation of various liquids and powders, a synthetic resin bag made of polyethylene is incorporated as an interior container inside the drum can, which is a shape-retaining member, and liquids and powders are stored in this synthetic resin bag The composite container made to do is used (refer patent document 1).

  Such a composite container has an advantage that the liquid, powder and the like can be sealed and stored, and at the same time, the stored liquid, powder and the like are not contaminated by the drum can.

  As shown in FIGS. 7A and 7B, the above-described synthetic resin bag 1 is formed to have a size that can be accommodated in the drum 2 and the top 4 is filled with a liquid or powder or the like. The tube port 4 is attached on the top plate 3 of the synthetic resin bag 1 by welding so as to communicate with the inside, and liquid, powder, etc. from the tube port 4 into the synthetic resin bag 1 are attached. After storage, the plastic bag 1 must be sealed by itself or tied with a string or the like, and then stored between the top plate 3 of the synthetic resin bag 1 and the lid 5 of the drum 2. For this reason, the tube opening 4 is required to have an appropriate length and flexibility to be folded.

  Conventionally, the manufacturing method of the above-described tube port 4 is made of a tube port body 6 formed in a cylindrical shape with a predetermined length using a flexible thermoplastic synthetic resin, and the lower end of the tube port body 6 using the same thermoplastic synthetic resin. The lower end cylinder 7 formed by providing a flange welded to the top plate 3 of the synthetic resin bag 1 around the lower outer periphery of the cylinder body provided outside, and the upper end portion of the cylinder mouth body 6 using a thermoplastic synthetic resin It is manufactured using the upper mouth tube 8 that is attached in a state of being fitted to the upper mouth tube and retains the upper end of the tube mouth body 6 in an open shape.

First, the tube body of the lower mouth tube 7 is externally fitted to the lower end of the tube mouth body 6 and this fitting portion is thermally welded, and then the upper mouth tube 8 is fitted to the upper end of the tube mouth body 6 and this fitting is performed. The parts are heat-welded, and the thus-formed tube opening 4 is attached by heat-welding the flange of the lower mouth tube 7 on the top plate 3 of the synthetic resin bag 1.
Japanese Utility Model Publication No. 4-14364

  By the way, in the conventional manufacturing method of the tube port 4 as described above, since the upper port tube 8 and the lower port tube 7 are separately heat-welded to the tube port body 6, the heat welding is a two-step process, and there are many steps. There is a problem that the production efficiency is low and the production cost is high.

  Accordingly, an object of the present invention is to improve the manufacturing efficiency by reducing the number of processes by enabling the lower mouth tube and the upper mouth tube to be simultaneously welded to the body of the tube mouth in the manufacture of the tube mouth as described above. Another object of the present invention is to provide a method for manufacturing a cylindrical opening for a synthetic resin bag that can reduce manufacturing costs.

  In order to solve the problems as described above, the present invention is formed in a cylindrical shape having a predetermined length using a thermoplastic synthetic resin, and the inner layer is a heat-weldable material of the same material, and the outer layer is On the outer periphery of the lower end of the cylinder body to be provided externally to the cylinder mouth body, using a cylindrical mouth body that is a material that is non-thermally welded to the same material and other materials, and a thermoplastic synthetic resin that can be thermally welded to the inner layer of the cylinder mouth body. A flange that is welded to the top plate of the synthetic resin bag is formed around, and a lower mouth tube for fixing the lower end portion of the tube mouth body to the top plate of the synthetic resin bag, and an inner layer of the tube mouth body are thermally welded. Using a possible thermoplastic synthetic resin, using the upper mouth tube attached in a state of being fitted inside the upper end portion of the tube mouth body, the bottom half of the tube mouth body is folded back from the middle position in the length direction, A double cylinder with an inner layer on the outside of the folded part Next, with respect to the free side end portion of this double cylinder, the upper mouth cylinder is fitted inside the cylinder mouth body, and the cylinder of the lower mouth cylinder is fitted outside the cylinder mouth body. A configuration is adopted in which the fitting portion between the upper mouth tube and the tube mouth body and the fitting portion between the lower mouth tube and the tube mouth body are thermally welded simultaneously.

  Here, the cylinder body has polyethylene as the inner layer and nylon as the outer layer. The former polyethylene is heat-welded with the same material, whereas the latter is non-heat-welded to the same material and other materials. Therefore, if the cylinder mouth body is formed in a double cylinder state in which the lower half is folded back from the middle position in the length direction, the overlapping surfaces of the double cylinders will be overlapped with nylon. The overlapping surface of the double cylinder does not weld at the time of heat welding the main body, the upper mouth cylinder and the lower mouth cylinder.

  In addition, the lower mouth tube and the upper mouth tube are formed into a molded product that is slightly thicker than the tube mouth body using the same material as the inner layer of the tube mouth body, and welded to the tube mouth body, thereby forming a cylindrical shape of the tube mouth body. The shape retention is improved.

  The above-mentioned heat welding is a heating rod positioned on the outside of the barrel of the upper mouth tube and the bottom mouth tube, and the fitting portion of the lower mouth tube and the mouth port body and the upper mouth tube, The fitting portion of the tube opening main body is sandwiched from inside and outside, and the two fitting portions are heat-welded at the same time, and the entire circumference of the fitting portion is heat-welded.

  At this time, the overlapping surface of the double tube of the folded tube port body is nylon and does not heat-weld, and the double tube is not completely folded, and the double tube is not completely folded at the free end of the double tube. Even if the outer layer of the tube mouth body protrudes inside or outside, this part is non-thermally welded with other materials such as nylon, so it may be welded to the upper mouth tube or the lower mouth tube. No.

  According to this invention, the upper mouth tube is externally fitted inside the free side end portion of the tubular mouth body folded back so as to form a double tube, and the lower mouth tube is also externally fitted to the outside, and in this state, Since the fitting part of the tube port body and the fitting part of the lower mouth tube and the tube port body are thermally welded at the same time, the heat welding in the manufacture of the tube port attached to the top plate of the synthetic resin bag can be performed in one step, Manufacturing efficiency can be improved by reducing the number of steps, and the manufacturing cost of the tube opening can be reduced.

  In addition, since the outer layer of the tube opening body is non-thermally welded with other materials, the double tube is temporarily incompletely overlapped in the welding process, and the outer layer protrudes from the free end. However, this portion is not welded to the upper and lower mouthpieces in the welding step, so that defective products are not generated.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The tube port 11 of the present invention which is welded so as to communicate with the inside on the top plate 3 of the synthetic resin bag 1 shown in FIG. 7 is formed in a thin cylindrical shape with a flexible thermoplastic synthetic resin as shown in FIG. The tube mouth body 12 is welded to the lower end portion of the tube mouth body 12, and the lower mouth tube 13 that fixes the lower end portion of the tube mouth body 12 to the top plate 3 of the synthetic resin bag 1 is fitted into the upper end portion of the tube mouth body 12. It is formed with the upper mouth tube 14 welded in the state.

  As shown in FIG. 2, the cylindrical mouth body 12 is formed into a flexible tube shape that has a necessary length and diameter and can be folded by extrusion molding or the like using a thermoplastic synthetic resin. The inner layer can be heat-welded with the same material such as polyethylene, and the outer layer has a two-layer structure in which non-heat-welding is performed between the same material such as nylon and other materials.

  The lower mouth tube 13 is made of a thermoplastic synthetic resin that can be thermally welded to the inner layer of the tube mouth body 12, and has a tubular body 15 having an inner diameter that is fitted on the tube mouth body 12, and is provided on the outer periphery of the lower end of the tube body 15. A vacuum flange 16 welded onto the top plate 3 of the synthetic resin bag 1 and a shape retaining rod 17 provided so as to project outward in a V-shaped cross-section are connected to the upper end of the cylindrical body 15 by vacuum. It is formed by integral molding by a method such as molding.

  The upper mouth tube 14 is made of a thermoplastic synthetic resin that can be heat-welded with the inner layer of the tube mouth body 12, and a cylindrical body 18 that fits inside the cylinder mouth body 12, and is provided on the outer periphery of the upper end of the cylinder body 18. The circular flange 19 is integrally formed by a method such as vacuum forming.

  The upper mouth tube 14 and the lower mouth tube 13 are thicker than the tube mouth body 12, and improve the cylindrical shape retention with respect to the upper and lower ends of the tube mouth body 12.

  Next, the manufacturing method of the cylinder opening using the said cylinder opening main body 12, the upper opening cylinder 14, and the lower opening cylinder 13 is demonstrated.

  First, the vertically long cylindrical mouth body 12 shown in FIG. 2A is folded back from the middle position in the length direction to the outside as shown in FIGS. 2B and 2C. Overlapping each other, that is, a non-thermal welding layer such as nylon is overlapped, and an inner layer, that is, a welding layer such as polyethylene appears on the outer side of the folded portion, and then, as shown in FIG. The cylindrical body 18 of the upper mouth cylinder 14 is fitted into the inner side of the mouthpiece main body 12 with respect to the free side end of the double cylinder, and then the lower mouthpiece 13 is placed outside the mouthpiece main body 12 as shown in FIG. The cylindrical body 15 is externally fitted.

  In this state, as shown in FIG. 5, the fitting portion of the upper mouth tube 14 and the mouth opening body 12 and the fitting portion of the lower mouth tube 13 and the tube mouth body 12 are overlapped by the same material by heat-weldable polyethylene. The overlapping surface of the cylindrical mouth body 12 that is a heavy cylinder is overlapped with nylon that is non-thermally welded between the same material and another material.

  As shown in FIG. 5, the rack 20 is positioned on the inner periphery of the cylinder 18 of the upper mouth tube 14, and the heating rod 21 is exposed to the outside of the cylinder 15 of the lower mouth cylinder 13. The free side where the heating rod 21 is pressed against the cylinder 15 of the lower mouth cylinder 13 through the non-welding sheet, and the cylinder 15 of the lower mouth cylinder 13, the cylinder 18 of the upper mouth cylinder 14, and the cylinder mouth body 12 are overlapped. By simultaneously sandwiching and heating the end portion, the fitting portion in which the cylinder 15 of the lower mouth tube 13 and the tube mouth main body 12 are in close contact with each other, and the fitting portion in which the tube body 18 of the upper mouth tube 14 and the tube mouth main body 12 are in close contact with each other. At the same time, heat welding is performed in one step.

  The above-mentioned heat welding is performed annularly over the entire length in the circumferential direction with a predetermined width in the vertical direction, and during this heating, the inner surface of the free-side end part of the double-cylinder double side is the same material. And since it is a non-thermal welding layer between other materials, the overlapping part of the tube opening body 12 will not be welded.

  Even if one of the double cylinders protrudes from the free side end of the double cylinder due to the dimensional accuracy when the cylinder mouth body 12 is folded back to the double cylinder state, the surface is exposed. Since the nylon of the outer layer of the barrel opening body 12 is not welded to polyethylene which is another material, the protruding portion of the outer layer of the barrel opening body 12 is welded to the lower barrel 13 and the upper barrel 14. It will not be defective.

  When the above-described heat welding is completed, as shown in FIG. 6, when the lower mouth tube 13 and the upper mouth tube are separated from each other vertically, the tube mouth body 12 is pulled out from the inside of the lower mouth tube 13 and extends into a cylindrical shape. Thus, the tube port 11 is completed in which the lower tube 13 and the upper tube 14 are thermally welded to the lower end and the upper end of the tube port main body 12, respectively.

  The cylinder port 11 manufactured in this way is similar to that shown in the conventional example of FIG. 7 by thermally welding the flange 16 of the lower port cylinder 13 to the top plate 3 of the synthetic resin bag 1 serving as an interior container. The main body 12 is attached so as to communicate with the inside of the synthetic resin bag 1, and after the liquid or powder is stored from the cylindrical mouth body 12 into the synthetic resin bag 1, the cylindrical mouth body 12 is bound by itself, or The inside of the synthetic resin bag 1 is hermetically sealed with a string or the like, and is stored in a folded state between the top plate 3 of the synthetic resin bag 1 and the lid 5 of the drum can 1.

  Moreover, when taking out liquid, powder, etc. from the inside of the synthetic resin bag 1, the lid 5 of the drum can 1 may be removed and the top plate 3 of the synthetic resin bag 1 may be cut.

The exploded perspective view of the component used for manufacture of the cylinder mouth concerning this invention (A) thru | or (C) is a perspective view which shows in order the bi-folding process of the cylinder opening used for manufacture of the cylinder opening concerning this invention in order The perspective view which shows the fitting state of the cylinder mouth main body and the upper mouth cylinder which were folded in half The perspective view which combined the lower mouthpiece with the fitting thing of the mouthpiece body and the upper mouthpiece Partially cutaway front view showing the state of thermal welding of the cylinder mouth body, the lower mouthpiece and the upper mouthpiece The perspective view which shows the extended state of the completed cylinder opening (A) is a longitudinal front view showing a state in which a synthetic resin bag using a conventional tube opening is housed in a drum can, and (B) is a perspective view showing the same synthetic resin bag and its tube opening portion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Synthetic resin bag 2 Drum can 11 Tube port 12 Tube port main body 13 Lower port tube 14 Upper port tube 15 Tube 16 Flange 17 Shaped rod 18 Tube 19 Flange 20 Plate 21 Heating rod

Claims (1)

A material that is formed into a cylindrical shape of a predetermined length using a thermoplastic synthetic resin, and whose inner layer is heat-weldable with the same material, and whose outer layer is non-heat-welded to the same material and other materials And a flange that melts on the top plate of the synthetic resin bag at the outer periphery of the lower end of the cylindrical body provided outside the cylindrical mouth body, using a thermoplastic synthetic resin that can be thermally welded to the inner layer of the cylindrical mouth body. A lower mouth tube for fixing the lower end portion of the tube mouth body to the top plate of the synthetic resin bag, and a thermoplastic synthetic resin that can be thermally welded to the inner layer of the tube mouth body, and the tube mouth body. The upper mouth tube attached in a state of being fitted inside the upper end of the tube, the lower end of the tube mouth body is folded back from the middle position in the length direction, and the inner layer appears outside the folded portion. Formed in the state of a heavy cylinder, then against the free end of this double cylinder The upper mouth tube is inserted into the inside of the tube mouth body, and the cylinder body of the lower mouth tube is fitted onto the outside of the tube mouth body. In this state, the fitting portion of the upper mouth tube and the tube mouth body and the lower mouth tube and the tube mouth body are fitted. A method for producing a cylindrical mouth for a synthetic resin bag, characterized in that the fitting portions are simultaneously heat-welded.

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